The formation of extracellular vesicles (EVs) is induced by the sphingolipid ceramide. How this pathway is regulated is not entirely understood. Here, we report that the ceramide transport protein (CERT) mediates a non-vesicular transport of ceramide between the endoplasmic reticulum (ER) and the multivesicular endosome at contact sites. The process depends on the interaction of CERT's PH domain with PI4P generated by PI4KIIα at endosomes. Furthermore, a complex is formed between the START domain of CERT, which carries ceramide, and the Tsg101 protein, which is part of the endosomal sorting complex required for transport (ESCRT-I). Inhibition of ceramide biosynthesis reduces CERT-Tsg101 complex formation. Overexpression of CERT increases EV secretion while its inhibition reduces EV formation and the concentration of ceramides and sphingomyelins in EVs. In conclusion, we discovered a function of CERT in regulating the sphingolipid composition and biogenesis of EVs, which links ceramide to the ESCRT-dependent pathway.
|Journal||Journal of Extracellular Vesicles|
|State||Published - Jun 2022|
Bibliographical noteFunding Information:
Acknowledgement is made to the donors of ADR, a program of BrightFocus Foundation, for support of this research. Services and products in support of the research project were generated by the VCU Massey Cancer Center Lipidomics Shared Resource, supported, in part, with funding from NIH-NCI Cancer Center Support Grant P30 CA016059. We also thank the Department of Physiology at the University of Kentucky (Chair Dr. Alan Daugherty) for support. This work was supported by grants to EB (National Institutes of Health: R01AG034389, R01NS095215, R01AG064234; U.S. Department of Veterans Affairs: I01BX003643) and to SMC (BrightFocus Grant Submission Number: A20201464F; National Institute On Aging of the National Institutes of Health under Award Number P30AG028383). Additionally, this work was also supported by ZonMw Memorabel program project nr: 733050105, the International Foundation for Alzheimer Research (ISAO) (projectnr: 14545), Hersenstichting (projectnr: DR-2018-00274), the Interreg Europe EURLipids program (projectnr: 23) grants to PMM. We thank Dr. Gregory Frolenkov, Department of Physiology, University of Kentucky, Lexington, KY, for his advice and technical support in electron microscopy. Access to characterization instruments and staff assistance was provided by the Electron Microscopy Center at the University of Kentucky, member of the KY INBRE (Kentucky IDeA Networks of Biomedical Research Excellence), which is funded by the National Institutes of Health (NIH) National Institute of General Medical Science (IDeA Grant P20GM103436).
© 2022 The Authors. Journal of Extracellular Vesicles published by Wiley Periodicals, LLC on behalf of the International Society for Extracellular Vesicles.
- ER-endosome contact sites
- extracellular vesicles
ASJC Scopus subject areas
- Cell Biology